begin
public compile, eval, lambda

use cas.syntax: SyntaxError
use cas.base
use math

_eval_ = eval

SymbolicExpression = table(Type,"SymbolicExpression") {
   function string
      syntax.ast_to_string(self.value)
   end
}

function symbolic(s)
   return table SymbolicExpression{value = syntax.compile(s)}
end

function eval(s,m=null)
   return table SymbolicExpression{
      value = base.eval(syntax.compile(s),m)
   }
end

env_math = {
   pi = math.pi,
   e = math.e,
   sin = math.sin,
   cos = math.cos,
   tan = math.tan
}

function lambda(id,t)
   return _eval_("|{}| {}"%[id,str(t)],env_math)
end

end